Cannot delete 'Windows.old' in Windows 8.1

The upgrade to Windows 8.1 went without a hitch but I am left with three empty nested folders Windows.old\Windows\Prefetch which I have found impossible to delete. I have used administrative tools/ disc cleanup/clean up system files tried it from Safe Mode but nothing works. Error 0x80070091 The directory is not empty but according to File Explorer they are all empty. Any advice would be appreciated.

If all else fails, boot with a Puppy Linux or Ubuntu CD. Either boots into a Linux environment without installing to the hard drive. I have successfully deleted files/folders using this method when unable to do in Windows.

Thank you for your replies. I followed them all but no joy. I even restored a pre 8.1 image upgraded again and did a system file cleanup, like the first time all the files were deleted but the three empty nested folders Windows.old\Windows\Prefetch remain. I tried Puppy Linux setup but could not get it to work, it had some problem on my machine. What I need is a boot disc with a file manager included. Thank you all.

Have done that many times, says 'An unexpected error is keeping you from deleting this folder. If you continue to receive this error, you can use the error code to search for help with this problem. Error 0x80070091: The directory is not empty.' I checked that error and cannot find a fix applicable to Windows 8.1 that works.

Thank you for your replies. I followed them all but no joy. I even restored a pre 8.1 image upgraded again and did a system file cleanup, like the first time all the files were deleted but the three empty nested folders Windows.old\Windows\Prefetch remain. I tried Puppy Linux setup but could not get it to work, it had some problem on my machine. What I need is a boot disc with a file manager included. Thank you all.

Peter

I think the operative word here is "empty". Personally, I would not go through this much effort to remove empty folders.
But, I have a wife who would, so I understand.
If you couldn't get Puppy Linux to work, try Ubuntu.
If you want to stay within the Windows boot disk realm with a file manager included, you could try Ultimate Boot CD for Windows. That, however is getting long in the tooth and might not recognize SATA disks.
And if you want to continue trying, download the Windows Automated Installation Kit. Use it to create a PE disk. Boot to PE and use the command line to delete the folders.

It may seem like a lot of work, but this always works; remove the hard drive, then use a sata to usb adapter to attach the HD to another computer. It will show as an additional hard drive. Open the drive, find the file, and delete it that way. In cases where I'm going to format anyway, I've been able to delete any & all parts of the operating system like this.
If you don't have a sata to usb adapter, all I can say is everybody should have one. It the handiest tool I've run across in years.

The following is an addition to the registry which allows you to Take Ownership of a resource by Right Clicking. Paste it into Notepad and save it as a .REG file. Then double click it and load it into the registry. To use it navigate to folder you wish to own, right click and select Take Ownership. If the folder has a lot of files then make yourself a coffee while you wait. I got these from somewhere but I can't recall where now.

Success at last. After trying everything I ran a disc check on my SSD C:\ boot drive and I was able to delete Windows.old\windows\prefetch. Not sure why this worked. Thank you all for the interest you have shown.